It is well known that meat-processing plants generate significant amounts of solid organic waste material daily, and that the waste from such plants can be difficult and expensive to treat. Meat processing plant waste streams typically contain blood, fat, muscle, bone, and intestinal contents, mixed into many gallons of wash-down water. Thus, the waste effluent may potentially contaminate water supplies if not properly treated, and the amount of organic matter lost through that treatment may be large.
For economic as well as environmental reasons then, many meat-processing facilities strive to reclaim solid organic material from the processing stream. As indicated above, the removal of organic waste is critical from an environmental standpoint, and in fact both federal and municipal governments typically place tight restrictions on the total dissolved solids, chemical oxygen demand (COD), biological oxygen demand (BOD) and total organic carbon (TOC) of water discharged into local sewers, rivers, or municipal wastewater treatment plants.
To comply with these standards, waste material is typically treated with industrial strength FeCl.sub.3 followed by the addition of cationic or anionic polymers to induce flocculation and facilitate subsequent solids removal. This process generally occurs at a low pH of about 6.
While the above process is generally effective to decontaminate the water, the removed solids have not been shown to have any independent commercial value. In particular, the removed solids have not been accepted as an animal feed ingredient due to the fact that many animals refuse to eat feeds containing significant amounts of FeCl.sub.3. Consequently, the removed organic solids are typically transported to and deposited in a landfill. Not only does this entail significant transportation and dumping costs, but this practice results in the continued buildup of already overcrowded landfills.
A need therefore exists for a process that removes organic material from waste streams while simultaneously creating a product with independent commercial value. The present invention addresses that need.